/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.launcher3;

import android.view.View;

/**
 * Interface for initiating a drag within a view or across multiple views.
 * 
 */
public interface DragController {

	/**
	 * Interface to receive notifications when a drag starts or stops
	 */
	interface DragListener {

		public abstract int getDragAnimationXOffset(View paramView);

		/**
		 * A drag has begun
		 * 
		 * @param v
		 *            The view that is being dragged
		 * @param source
		 *            An object representing where the drag originated
		 * @param info
		 *            The data associated with the object that is being dragged
		 * @param dragAction
		 *            The drag action: either
		 *            {@link DragController#DRAG_ACTION_MOVE} or
		 *            {@link DragController#DRAG_ACTION_COPY}
		 */
		void onDragStart(View v, DragSource source, Object info, int dragAction);

		/**
		 * The drag has eneded
		 */
		void onDragEnd();
	}

	/**
	 * Indicates the drag is a move.
	 */
	public static int DRAG_ACTION_MOVE = 0;

	/**
	 * Indicates the drag is a copy.
	 */
	public static int DRAG_ACTION_COPY = 1;

	public static final int DRAG_ACTION_COPY_AND_ICON_CENTER = 2;

	public abstract void startAnimation(View animationView, float fromX,
			float toX, float fromY, float toY, float xOffset, float yOffset,
			int duration);

	/**
	 * Starts a drag
	 * 
	 * @param v
	 *            The view that is being dragged
	 * @param source
	 *            An object representing where the drag originated
	 * @param info
	 *            The data associated with the object that is being dragged
	 * @param dragAction
	 *            The drag action: either {@link #DRAG_ACTION_MOVE} or
	 *            {@link #DRAG_ACTION_COPY}
	 */
	void startDrag(View v, DragSource source, Object info, int dragAction);
}
